Artificial refrigerating system



troit, county of Wayne, State of Michigan,

liatizientedl Dec'. 30, 1924. r-

unfrei) s TAr-E JAMES H. DENNEDY, or nnrnor'nfmlcmehn Americain. REFRIGERATING :s YsTni.

:Application tiled December 10, 1921. Serial No. 521,43?.

To all whom it may'concem': *Be it known that I, JAMES H. DENNEDY, a

citizen of the United States, residing at Dehave invented a certain new and useful Improvement in Artificial Refrigerating Sysl tems; and declare the following to be a full,

" clear, and exact description .of the same,

chloride orsirriilar chemical is compressedand`liqueiied and then lcooled and allowed to expand in a coil-within alstorage com':

partment, brine tank lor, the like, and the' particular feature of-tfhis invention'is in. the' provision of means to control the teniper`a` ture lof -the storage compartment or body to "becooled through variation in pressure vof the'expansion sideof thev system. Theapvparatus is intended to be'opcrated by an electric motor as is usual` with systems of thisv lcharacter but other motive power may be utilizedjif desired. The means employed for stopping and starting' the electric-motor,- sfis preferably used, is an electric"switchl adapted toconnect andfdisconnect the ino-- ltor with-the' source of energy. Heretofore,l

-the temperature of the storage compartment is maintained between 'certain high and 'low limits by means of aV thermostat A'which "is adapted either throughfthe expansion and contraction of av bimet allic element'v or actuation of other means sensitivetotempera'- ture change toopen and lclosefthe circuit-` `to themotor. In theapparatus' herein disclosed `a pressure controlled switch isutilized subject to the influence of variation in p1e s' sure in the'expansion side of `the system, a i' certain vhigh'gpressure-resulting. in the=clos` ing of 'the switch-"to startthe system into operation, and l'a 'predetermined low pres# sure opening the switch and "causing cessation of loperation ofthe' motor, vthe switch'` being adjustable to permit the deviceto 4be set to operate at .different pressures. lAn

- Aautomaticallyj operatiiig lv alve 'isj also emr'4 ployed between the high 'andlow pressure sides ofthe circulating .system` and pref-3' erably with. a pressure' operated .device "for maintaining 'the temperature ofthe'stor'age compartmentwithin 'certainlimita I prefer' Y to employ an automatic valve of a' character.

to maintain a constant' uantity of refrigerant in the'. expansion side of the system.' In systems'o'f 'this general character, upon, cessation of operation ofthe compressor, the

pressure on the low pressure sides of the system tends to increase due to absorption 'of heat from the body or compartmentv being cooled.v With pressure .controlled device controlling operation of the refrigeratingr apparatus, tlie ressure yof the expansion side maybe hel -between CertainflmtSof high and lowfpressure by which means the'4 temperature :ofV the refrigerated compart-l ment is directly controlled bythe apparatus This application' constitutes a f "continuay' tion 1n .pa-rtl of my 'application Seriall No.

493,266, ii1ed"'August 18,V 1921, jcevrlig,

artificialrefi-igerating apparatus. The 'drawing presented 4 herewith illustratingfthe 'preferred form 'of apparatus i' embodying my linvention is I )ractically` cluding'a condenser, indicated at'. 3, and the '80 diagrammatic-in fori'n showing a" coiiipresfl sor indicated. at. 1, a compartment or' bod to berefrigera-ted indicated at Q, the hi 4 pressure -side of `the' circulating-system, in-

low pressure Iside lindicated at'4, the low pressure line having` a coil f5 (which 'may be of any'de'sired -for-m) 'located ithin'the storage compartment orbody to erefri'g# erateil,A the "temperature 'of 'which it is dcsired tocon'trol. As will be readily understood, the Vcoils 5 l may beusedin a brine tankV or ,iii conjunction with'any "other body desired to-befused."

The control apparatus is indicated genlarger yscale in comparison to Vtliejcoinpressor 'than wouldbe the casein actual-construction, being here-'shown o n an `enlarged -j scale to i'noreclearlyv show the lseveral parts of the device indetaL The compressori' may b eof any approvedA electric type preferably one operated an motor (not here shown) connected with 4the 'sha-tf 7 of the compressor, it being under- .stot'zduthat the--compreor discharges .into

'the line 3I which is connectedto the "upper Il" imm the line 4,; 4'Bumen thezhighpressum' line' v3 and low' prcssllre line 4 and coil5 of the expansion side, 'I provide anV expansion valve vil'idjcat'ed generally by the numeral f valve 'the' fluid is passed from the high pres- `sure side to the low pressure side solelyby 70. 'I do not `wish lto be understood as.

limiting myself to the use of the particular form of expansion valve here shown but prefer to u se this type of valve'which is of a character to maintain a constant y'volume of refrigerant in the low pressure side of the system. The valve shown consists of `a. valve member 8 of needle t pe adapted t`o open or close the end ofthe ine 4 opening into the chamber 9 in which the ,"valve'is positioned. This valve 8 is pivotvariation in level of the Huid in the chamber 9 tending to'main-tain a certain volume of fluid at the high pressure side and pass fluid into the low pressure side as rapidly as it is removed therefrom..

' With any'refrigerant, the tempera-ture of the liquid refrigerant or its saturated vapor in the expansion coil of the system bears a definite relation to the pressure thereofthat is, for instance with sulphur' dioxide. a gauge pressure of approximately 4.6 pounds per square inch indicates a temperature of the liquid refrigerant or its saturate vapor-c1525 degrees F., and with a gauge i pressure of 2.5 pounds per square inch the temperature of-t-he sulphur dioxide is f a-pproximately 20 degrees F., and I have taken means of a line 14 with the Yexpansion line 4. The pressure control device consists of a casing 15 within which is a circumferentially corrugated cylinder 16 of well known l.advantage of this -fact by this pressure oon. trol device which is directly connected by Ward through the cap to an electric switch of the knife blade type which, it is to be understood, has a blade 23 adapted to be brought into engagement wit-h the contactl member 24 of the control circuit wires 25 and 26. 4 Upward movement of `the member 17 and rod 22 caused by an increase in pressure in the line 4, as will beunderstood, will close the switch and close vthe circuit to the electric motor starting the same and operating the compressor, and a decrease in pressure in the line 4 suliicient to permit the spring- -to act and force the nember 17 downward to the position show-n in lthe drawing opens the switch, cutting the current vsupply oil from the motor and thus stops operation of the compressor.

The operation of the system will be understood from the following: Let it` befassumed that it is desired to maintain the storage compartment yor bod 'to be cooled at a temperature ranging rom; 25 to 30 degrees lt., and let it be 'assumed that sulphur dioxide is used as a'refrigerant. The principle of.v operation Iwill apply to any refrigerant v but the numerical values depends upon. t-heparticular refrigerant used. The amount of heat passed through any conductor in a .unit of timey may be ex-l pressed by the equation Q =A (T'l) XC in which Q `equals the quantity of heat transmitted in a unit of time 'and thereforefis the rate of flow of heat through the conductor. Ai `equa-ls' the effective area of the conductor through which the heat will pass. 'T' equals, the temperature ot the source of heat-thatis in this instance the temperature ofthe body to be cooled. T" equals the .temperature of the'medium which absorbs or takes up heat from the warmer bodies and in this case is the temperature of the boiling refrigerant. C equals the co'eicient which becomes a con stant for similar conditions.

ln any lrerigerating system with the comtype capable of expansion and contraction /pressor running at constant speed, Q is prac longitudinally of' its axis. The lowerend of this memberv 16- is sealed to a plate 17 and the upper `end is sea-led vto a cover 18 set in place on the casing 15. This provides a sealed chamber 19 between Vthe corrugated member 16 and casing'15, the chamber 19 being open to the line 14. As shown in the drawing', the plate` 17 is at its lowermosty position engaging against the upper end 'of the inlet for the line 14 but on pressure accumulating in the vline 4 and* 14, this member 1'7 is raised.l Within the corrugated cylinder 16 is a spring 20 engaging at the ,upper end against a. cap 21l and at the lower end-'against the member 17, the spring tending to expand the member 16 and force v the member 17 to the lowermost position a s shown in the drawing. A rod 22 is care ried 1n the base member 17 and extends uptically a const-ant quantity. A is also con-l stant when'a loat valve is introduced as shown here to control the flow of compressed refrigerant from the chamber 9 into the ex- 're rigerating medium must be 20 degrees F., and with sulphur dioxide the pressure in Macnee storage compartment the temperature there-f of falls finally reaching the minimum of 25' i degrees F., at which time the temperature of the refrigerant in the expansion coil must be 15 degreesF., vand has a gauge pressure of one-half pound per square'inch. Under this reduced pressure by action of the-spring -20 the switch will .be opened stopping operation of the motor and compressor. fs the storage compartment reaches'a temperature of 25 degrees F., and the temperature of the liquid in the coil 5 is 15 degrees F., heat will continue to dow lfrom the compartment into the refrigerant.. 1

Inasmuch as the .compressor is Astopped at this time this additional heat flowing into Y the refrigerant body will cause an increased the line 4 and coils 5 and when l pressure 111.

this pressure reaches about 4.6 pounds per square inch gauge pressure, vaporization will cease because the temperature of evaporation of sulphur dioxide at 4.6 gauge pressure is 25 degrees'F., Under these .conditions, when ythe storage compartment has reached a-temperature of 30 degrees F., the refrigerant body in the expansion -'coils has also reached the same degree of temperature at which temperature the pressure in the evaporating coils will be about 7 pounds per square inch which will close the switch and start the motor. The starting and stopping of the apparatus is thus controlled by varlation in pressure of the low pressure side of the system and the temperature of the storage compartment is maintained within a 5 degree range and there isthus v available a difference of pressure of 6.5 pounds per square inch for actuating the control switch. The data given refers only to stated temperatures but the switch member is made adjustable by.varying the tension o f a spring so that any, desired range oftemperature'at which it would be desired to `maintain al storage` compartment can be compensated for. With a thermostatically controlled switch the starting and stopping ofthe mechanism would be through a range of 2.4 pounds" per square inch because .the pressure corresponding to a temperature of 30 degrees F., .is 7 pounds and the pressurel corresponding 'to 25 degrees F. is 4.6 pounds per square inch gauge pressure. By the arl rangement. here described a relatively large operation offthe switch permitting only a. .60

difference, in pressure is made available for relative small variationA in temperature of the cooling'body.

It is evident from the foregoing that the device is simple and inexpensive; that the Ytemperature of the'` storage com artment maybe accuratelymaintamed by t e variation in pressure of the expansion line rather than by the temperature of the body or storage compartment being cooled and by the use of the float controlled valve,A the liquid refrigerant is automatically transferred from the high to low pressure side practically as fast as it accumulates, and a, practically constant maximum quantity of refrigerant maintained in. .the evaporating 'line which is the condition under which the most efficient results are obtained.

Having thus fully described my invention, what I claim and desire yto secure'by Letters Patent of the United States is- 1. In'an artificial refrigerating apparatus including` a compressor, a body to be refrigerated, and a circulating system for the refrigerant having a high and a low pres-y sure side, the low pressure side being arranged to effect temperature'changes in the body to be refrigerated, the Vcombination therewith of valve means automatically actuated to pass'refrigerant from the high-to thelow pressure side only upon an increase of thequantity of liqiid refrigerant in thehigh pressure side a ove a predetermined amount, and a control' device for stopping,r and starting operation of the vcompressor operated through variation ,in pressure of the refrigerant in the low pressure side of the system caused by variation of tempera-y tu'el in the refrigerant in the low pressure s1 e. l

2. In an artificial refrigerating system including a ,power-apparatus, a compressor, high and low pressure lines for circulation of a refrigerant, of a oat controlled valve arranged to automatically discharge refrigerant from the high to the' low pressure side on an increasein quantity thereof in the high pressure 'Side above a "predetermined amount, a control device for starting and stopping thepower apparatus and loperathe control device comprisingan apparatus sensitive to variation in'pressure inthe low pressure line due to temperature change therein, and a bodyto be cooled providing the sole means through which the low pressure line is subjected to Iinfluence of heat.

3. In an artificial refrigerating `apparatus including a compressor, a circulating system having a high and lowpressure side, anda power appliance, the combination therewithA of'a device for controlling operationof the system comprising apparatus operating in conjunction with the compressor` to main= tain a substantially constant quantityof the refrigerant inthe 'low pressure side, and means 'operated by variatlon in the Vvapor 1 tension of the low pressure vside` to stop and. start the power appliance.. v

4. In an artificial refrigerating apparatus Y including a compressor,v operating means therefor anda circulating system for thel refrigerant having a high and low pressure side, of a refrigerator having a chamber to be cooled in which the low pressure.' side of the system is located, means operating in conjunction withthe compressor forpmaintaining a predetermined quantity ofrefrigerant in the loW pressure side, and a control device for starting andv stopping the power apparatus including a chamber open to the low pressure side of the system, and means in the chamber influenced by variation in lpressure. of the low pressure side to start and stop operation ofthe power apparatus.

5.'The combination in an artificial refrigerating system of a refrigerant circuit including a low pressure side anda high pressure side, a compressor, means for maintaining a constant volume ofliquid refrigerant in the low` pressure side, comprising a float valve actuatedby 'fluctuation in the levelof liquid refrigerant in one of said .sides, means responsive to pressure varia- Ltions in the low pressure side due,l to temperature change thereof for controlling said compressor, and a body to be cooled, ab-

sorption of heat in varying amount by the low pressure lside being substantially conf fined to heat from said body.

6. In an artificial refrigerating apparatus including a compressor, a body to be refrigerated and a circulating system for refrigerant having a high and alow pressure side, the low pressure` side being arranged to eff'ect temperature changes in the body to be r' refrigerated, the combination therewith of a valve for passingliqu'id refrigerant; from l the high pressure side tothe lovi7 pressure side, the liquid refrigerant forming a -trap to prevent passage of vaporized refrigerant from said high pressure side through saidvalve, means for closing said val-ve when there is insufficient liquid for said trap, and a control device for said compressor, op- -erating through variation in pressure in the refrigerant in the `low pressure side of the system caused -byvariation of temperature of the refrigerant in said low pressure side.

, 7. A refrigeratingl apparatus comprising a circulating systeinhaving a l'ow pressure side in heat absorbing relationl to `the body tobe cooled for containing and vaporizing refrigerant, means for withdrawing vaporized refrigerant from the low pressure side,means responsive to'pressure change in the vaporized refrigerant in the low pressure side for controlling said withdrawing means,

and means for automatically supplying liquid refrigerant -to theilow pressure side as required for maintaining a constant area lof heat absorption for the liquid refrigerant 8; A refrigerating apparatus comprising i a refrigerantcirculating system having a vlow pressureside forming'a 'vaporizing chamber in heat absorbing relatioii tothebody to be "cooled, means fon'witlidrawing vaporized refrigerant from the low pressure side, means for returning liquid refrigerant to the low pressure side and for maintaining aconstant level ofthe liquid refrigerant therein, and means responsive tosfiuctuation -in the vapor pressure in the low pressure side for controlling said withdrawing means.

9. An artificial refrigerating system comi prising a high pressure side and a refrigerant flooded low pressure side, means for delivering liquid refrigerant from the high pressure side to the low pressure side, means for withdrawing vaporized refrigerant from f the llow pressure. side; a body to be refrigerated with which the low. pressure side is in heat absorbing relation, means for main taining a constant area-of exposure with the body -of the liquid refrigerant in the low pressure side, and meansl responsive' to pressure fluctuations in the low ,pressure side lfor controlling withdrawal of liquid refrigerant from the low withdrawing means.

10. The combination 1n a refrigerating pressureside by said apparatus, of a vaporizing chamber, a body to be cooled in "heat imparting relation thereto, means for admitting liquid refrigerant to said chamber,' means for reducing the. pressure in said chamber, means for keepinga constant area of heat absorption between the body and the liquid refrigerant in the chamber, and means for controlling n said pressurereducing means`1n response to 100 pressure fluctuation in the chamber.

11.l The combination with a refrigerating apparatus comprising a high pressure side,

a low pressure side in heat absorbing relation tothe body to be coo1ed,means for withdrawing vaporized refrigerant from tlie low pressure side and for returning it in compressed form to the high pressure side, and means responsive to `pressure fluctuations in the low pressure side for controlling said first mentioned means, of means for passing sufficient liquid refrigerant from the high tothe low pressure vside to mainytain a constant area of liquid refrigerant eX- posed to the body to be cooled but .prevent ing passage `of vaporiz'ed refrigerant.

L spense to fluctuation in vapor pressure in the low pressure side for controlling the functioning of said exhausting means for the purpose of maintaining the pressure, and thereby the temperature, of the 10W pressureside between predetermined limits.

13. In a refrigerating apparatus tl-ie combination of a refrigbrant circulating system having a high pressure side for containing liquid refrigerant Aand a low pressure side for Vaporizing the refrigerant, means for passing liquid refrigerant from the high pressure side to the 10W pressure side, a body to be cooled in heattransferring relation to the low pressure side and supplying to temperature fluctuations tliereinvto 'control said exhausting means for keeping the temperature of tlie'low pressure side within predetermined limits by maintaining the,

vapor pressure therein between mined limits.

In testimony whereof, I sign this specification. i

JAMES H. DENN EDY.

predetervpressure in the low ypressurel side in reponse 

